Fuse-setting apparatus



Sept. 28, 1948. v. PJHAR'vl-:Y

USE-SETTING APPARATUS 2 Sheets-Sheet 1 Filed July 15, 1944 M u, v

ATTORNEY Sept. 28, ll948. v. P. HARVEY v FUSE-SETTING APPARATUS 2 Sheets-Sheet 2 Filed July 15, 1944 a l E im rra/PNEY Patented Sept. 28, 1948 FUSE-SETTING APPARATUS Valentine Pearce Harvey, Deptford, London, England, assignor to Molins Machine Company, Limited, Deptford, London, England Application July 15, 1944, Serial No. 545,163 In Great Britain August 12, 1943 2 Claims.

This invention concerns improvements in or relating to fume-setting apparatus (for example fuze-setting apparatus for use with anti-aircraft guns) of the kind having a fuse-engaging element for engaging the movable fuze-element of a shell, and an adjustable control-member which is intended to be adjusted according to the fuze time to be set and by its position determines the extent of movement that can be imparted to the movable fuze-element. Such fuze-setting apparatus will be referred to hereinafter as fuzesetting apparatus of the kind described. Usually theadjustable control-member 4comprises a stop on a worm-wheel driven by a follow-thepointer hand-wheel associated with the predictor dial which indicates the momentary fuzesetting for a moving target, the momentary position of the adjustable stop determining the eX- tent to which the movable fuZe-element can be moved, thus constituting an adjustable controlmember adjustable in accordance with the setting to be given. When an element carried by the driving member of the aforesaid fuze-engaging-element engages the adjustable controlmember the fuze-engaging element is caused to be disconnected from its driving member. Such a fuze-setter forms the subject of United States Patent application Serial No. 466,808.

An object of the present invention is to provide a simple and robust clutch device for automatically disconnecting and coupling the rotatable fuze-engaging element from and to its driving member at the appropriate times.

According to the present invention there is provided a fuze-setter of the kind described having a rotatable fuZe-engaging element, a rotatable driving member to rotate the latter and an adjustable stop, a clutch comprising a movable element mounted to rotate with said rotatable fnac-engaging element and pivoted so as to be capable of turning on engagement with the adjustable stop, a recess or slot in the region of said adjustable stop and into which the movable element is caused to move on being so turned, a driving pawl mounted for rotation with the movable element, a recess in the driving member to receive the driving pawl, a surface concentric with the axis of revolution of the driving member on which, when the movable element enters the recess or slot the driving pawl fits so as to prevent said movable element from turning on its pivot thereby holding the movable element in the recess or slot and locking the rotatable fuzeengaging element to the adjustable stop, the driving pawl and movable element being so ar- 2 ranged that movement of either into or out of its recess causes the other to move out of or into its recess, as the case may be, and means operable to return the driving pawl into its recess before a fuZe-setting operation.

Fuze-setting apparatus of the kind described made in accordance with the present invention will now be described and illustrated by way of example. The clutch about to be described is basically the same as that described and shown in Figures 4 and 5 in United States Patent application Serial No. 466,808, but modied in such a way that the pivoted catch pawl described in that specification for holding the movable stop against the adjustable stop is omitted from the present construction.

In the drawings:

Figure l is a perspective View partly broken away showing the clutch and its driving gear together with the worm wheel and the adjustable and fixed stops, the parts being in the position occupied When at rest and prior to a setting operation.

Figure 2 is a fragmentary view of the upper part of Figure 1 showing the parts in a position occupied during a setting operation and before the movable element engages the adjustable stop.

Figure 3 is a front elevation of the worm wheel shown in Figure 2 showing the location of the movable element therein.

Figure 4 is an exploded View of the movable element and its stud and bush.

Figure 5 is a view generally similar to Figure 2 but shows the parts in a diierent position, the movable element being in engagement with the fixed stop.

Figure 6 is a front elevation of part of the worm wheel shown in Figure 5 showing the location of the movable element therein.

Figure '7 is a view similar to Figure 1 showing the parts in the position occupied when reversal of the driving motion is about to start.

Figure 8 is a side elevation, partly in section, of a fuZe-setting apparatus constructed according to the invention.

For convenience the same references are used herein for parts similar to those described and shown in the aforesaid application, new or modified parts bearing references above IDO.

Referring to Figure 8, the fuze-setter is, except for details of the clutch, identical with that described in the aforesaid application and only a brief description is necessary here. The movable fuze-element is gripped and rotated by a rotatable fuZe-engaging element I, comprising a number of knife edges 2, the extent of rotation being determined by the relative positions of the fixed stop 3 and the adjustable stop 4 on the wormwheel 42. Meanwhile the round is held stationary by knives 7 in a member 8 which does not rotate. The gripping devices and 8 are supported on a hollow rotatable shaft 30 which is caused to approach a round for fuze-setting by the lever which is operated by cams 99, 9| on the camshaft 9 as described in the aforesaid application through a train of gears 94-91 froma motor 98. The fuze-engaging element rotates with the shaft 39, which is rotated at the appropriate times by a driving member or disc 3| which is fixed to a ring gear wheel 29. This gear is driven by a gear Wheel 28 coupled to a pinion 26 which is driven by a toothed quadrant 25 also receiving its motion from an annular cam 92 on the camshaft 9 through a roller 93 mounted on arm 99 formed integrally with the quadrant 25 and pivoted on a spindle |00.

Referringto the other gures of theV drawings, the driving gear consists of a ring gear wheel 29 which has attached concentrically therewith a driving disc 3| forming the driving member of the clutch and having an arcuate recess 32 in its periphery and a projection 33 on that side of the recess which is the leading side when the gear wheel is moving in the forward or fuzesetting direction (i. e. the direction indicated by the arrow C, Figure 2) in which it is rotated when the movable element 5 which is carried by the driven disc 35 of the clutch is moving from the xed stop 3 to the adjustable. stop 4. In the present case the adjustable stop comprises a shoulder marked 4 formed in the worm wheel 42 as in the construction described in the aforesaid application, but a further shoulder is provided so that between the two shoulders is a recess or slot |04. The worm-wheel 35 is the usual adjustable control member whose angular setting is determined by a worm (not shown) driven by a follow-the-pointer handle or any mechanical means to effect the same known purpose.

The driven element of the clutch comprises a disc 34 formed on the hub |34 and arranged concentric with and splined to the lhollow shaft 3G, Figure 8, of the fuze-setter. The disc 34 has a lug 35v in which is pivotally mounted a rocking nawl device or driving pawl 35, constructed as follows:

The pawl is formed as shown for example in Figure 2 as a bent double-armed lever or bellcrank fixed on the squared end 3T of a stud 38 pivotally mounted in the lug 35 of the driven element 34', the extremities of the two arms 36a land 36h of the bellcrank being shaped to coincide with aros struck from the pivotal axis of the rocking pawl. The arcuate recess 32 is made so as to be concentric with the axis of the beller-ank pivot when the members are in clutch-engaging position, that is as shown in Figure 2, and is of just suiiiciently greater radius Ithan the arc of the extremity of the arm 36a of the bellcrank` to allow the arm 36a to move into the recess; The driving member 3| has another concave part 39 on its peripherywhich is of smaller radius and which is struck from the same centre as the centre of the other arm 36h of the bellcrank. The movable element 5 is formed in one piece with the stud 38 (see Figure 4) and is so arranged as to engage lthe adju-stable stop-4 at the end ofthe forward or setting movement. As 'the movable element 5 engages thev adjustable stop itturns inwardly and enters the slot |94 between the two shoulders.

The leading corner of the movable element is chamfered to facilitate entry into the slot. The element is -so shaped that when it engages the adjustable stop the driving pawl 36 is rocked so that the arm 36a which lies in the recess 32 during the forward or setting movement (Figurev 2) Vis brought clear of the recess as shown in Figure'.

'1l-he driven element 34 is thus declutched from the driving disc 3| which continues to rotate in the direction of the arrow C, Figure 2, leaving the driven element 34 of the clutch stationary, see Figure 5.

The inside of the driving pawl 36 is arcuate and is adapted tohave an accurate sliding t on the concentric surface of the driving disc 3|. Thus as the movable element 5 enters the slot |04 the driving pawl engages the concentric surf-ace of the driving disc, whereupon the element is located in the slot and cannot leave the slot until the driving pawl is again in a position relative to the driving disc 3| in which it can enter tlhe dri-vingV recess 32 in Athe driving disc.

The driving disc 3| moves in the direction oi the arrow C fora distance suicient to allow the longest possible fune-setting to be accompli-shed wherever the adjustable stop may be, i. e. substantially to theV position shown in Figure 7 where the projection 33 on the ydriving disc is close to the fixed stop 3. After the disc 3| has moved lthis distance it is moved in the reverse direction (i. e. as shown by the arrow D, Figure 7), by the reverse movement of the gearing 25, 2S, 28, 29 operated .by the cam 92 on the camshaft 9, Figure 8. j

O-n the reverse movement of the driving disc 3|, the projection 33 on the driving disc eng-ages thel arm 35o of the driving pawl when the projection on the driving disc returns. into contact with the driving pawl. At the same -time the recess 32 returns 'into position beneat'h the arm 36a ofthe driving pawl, so that the pawl is once more free to turn. The engagement between the projection 33 and the arm 36o causes the drivingpawl to rotate on its axis and turn so that its end 36a moves into the driving recess 32. This ,movement of the driving pawl turns the movable element I5 so that it rotates clockwise on its axis as viewed in Figure 6'. As will be seen, the slot |94 is arranged substantially tangenti-ally to the axis' of rotation of the driving disc 3 so that the movable element 5', which turns clockwise on its axis as it also moves bodily in a clockwise direction (see, arrow D, Figure 7), moves away from the adjustable stop 4 tangentially and is thus enabled to be drawn out of the slot |04 due to these combined movements. Consequently the movable element is released' from the adjustable stop and returned by continued rotation of the driving `disc 3| to the starting position against the xed stop 3 (Figure 1) ready for setting anotherfuze.

From the above it will be seen that the construction. is. simple and positive in its action and that as soon as the movable element 5 engages the adjustable stop 4 it is locked to the adjustable stop, andthe driving disc continues to rotate untili-t is brought torest at the end of its driving stroke. In the. meantime any movement which may be made by theY adjustable stop, that is by movements of the wormwheel 42, is imparted to the movable element and so the fuZe being set is always up to date with the fuze setting signalled.

By the construction laccording to Ithe present invention the operation of locking and unlocking the movable element and the adjustable stop is positive and there is a minimum amount oi Wear and shock, all yof which lcontribute to accuracy of setting. Moreover, the construction is simple and cheap and is capable of being cheaply produced.

What I claim as my invention and desire to secure by Letters Patent is:

l. A fune-setter of tHe kind described having a rotatable fuZe-engaging element, a rotatable driving member to rotate the latter, a control member including an adjustable stop to determine the extent to which the rotatable fuZe-engaging element is to be moved, a part driven with and rotatable with the rotatable fune-engaging element, a clutch comprising a movable element mounted on said driven part and arranged to move into engagement with said adjustable stop,

said movable element being pivoted on said part so as to be capable of turning on engagement with Ithe adjustable stop, a recess formed in said control-member adjacent said adjustable stop and into which the movable element is caused to move on being so turned, entry of said movable element into said recess locking the movable element to the adjustable stop, a driving pawl mounted for rotation with the movable element and adapted to drive said driven part, said pawl l being pivoted so as to be capable of turning with the movable element and disconnecting the drive to said driven part when the movable element is locked to the adjustable stop, a recess in the driving member to receive the driving pawl, said driving member having a surface concentric with the axis of revolution thereof on which, when the movable element enters the iirst named recess the driving pawl ts so as to prevent said movable element from turning on its pivot thereby holding the movable element in the rst named recess and locking the rotatable fuZe-engaging element to the adjustable stop, the driving pawl and movable element being so arranged that movement of either into or out of its recess causes the other to move out of or into its recess, as the case may be, and means operable to return the driving pawl into its recess before a fuze-setting operation.

2. In a fuze-setter of the kind described including a rotatable fuZe-engaging element, a

driving member for rotating said fuez-engaging element in one direction to set the fuze and in the opposite direction to return said element to its zero position before the next fuZe-setting operation and a control-member including an adjustable stop for determining the end of the rotational setting movement of the fuse-engaging element, a clutch for connecting and disconnecting the driving member to and from the rotatable fuZe-engaging element comprising a driven part rotatable With the fuZe-engaging element, a movable element pivotally mounted on said driven part and arranged to engage and be turned on its pivotal axis by said adjustable stop during the rotational setting movement of the fuze-engaging element, the control-member having a slot formed therein adjacent said adjustable stop into which the movable element is moved when turned on its pivotal aXis by engagement with the stop, entry of said element into said stop locking the driven part to the controlmember, a driving pawl pivotally mounted on said driven part and so connected to said movable element that both said pawl and said element turn on their pivotal axes Whenever one of them is turned, a driving member having a recess formed therein adapted to receive said driving pawl, said pawl and recess being so arranged as to provide a driving connection between said driving member and driven part when the pawl lies in the recess, said pawl and movable element being so arranged that the pawl is moved out of said recess by turning on its pivotal axis when the movable element engages and is turned by said adjustable stop, said driving member also having a surface concentric with the axis of rotation thereof on which the driving pawl is supported and by Which the pawl and movable element are prevented from turning on their pivotal aXes as long as the pawl is out of said recess, and means operable during movement of said driving member in the direction to return the fuZe-engaging element to its Zero position for moving the driving pawl into said recess and simultaneously moving said movable element out of said slot.

VALENTINE PEARCE HARVEY.

No references cited,` 

